This proposal considers the following working model to explain how polyclonal T cell stimulation can promote human SLE. 1) Naturally- occurring environmental agents can trigger in vivo polyclonal T cell activation in all hosts. 2) Such polyclonal T cell activation normally results in polyclonal activation of both helper T cells and downregulatory T cells. 3) The polyclonally activated helper T cells have the capacity to promote activation and differentiation of many (if not all) B cells, including those capable of producing pathogenic autoantibodies. 4) The polyclonally activated downregulatory T cells counterbalance this autoimmunity-promoting response, at least in part, via physical lysis of cells crucial to polyclonal Ig production (including the B cells themselves). 5) The numerically small CD8+56+ T cell subset is the predominant effector of this polyclonal downnregulatory CTL activity. 6) Polyclonal downregulatory CTL activity mediated by CD8+56+ T cells is impaired in SLE, allowing for enhanced survival of the cells crucial to polyclonal Ig production and enhanced opportunity for the relevant B cell to produce pathogenic autoantibodies. 7) The CTL defect is a predisposing factor in SLE pathogenesis. This proposal will focus on 4 specific questions based on this working model. 1) Do normal CD8+56+ T cells potently downregulate polyclonal Ig production, and is such CD8+56+ T cell-mediated downregulation impaired in SLE? 2) How are normal downregulatory CD8+56+ T cells generated, and what are the defects in SLE? 3) How do normal CD8+56+ T cells effect their downregulation, and what is the defect in SLE? 4) Does the SLE defect in CD8+56+ T cells antedate onset of overt clinical disease? The answers to these questions should shed considerable light on fundamental pathogenetic immune disturbances in human SLE.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
2R01AR041006-04A2
Application #
2395752
Study Section
Immunological Sciences Study Section (IMS)
Project Start
1993-08-12
Project End
2001-06-30
Budget Start
1997-07-10
Budget End
1998-06-30
Support Year
4
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Southern California
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
041544081
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Stohl, William; Xu, Dong; Kim, Kyoung Soo et al. (2004) MHC class II-independent and -dependent T cell expansion and B cell hyperactivity in vivo in mice deficient in CD152 (CTLA-4). Int Immunol 16:895-904
Stohl, W; Metyas, S; Tan, S-M et al. (2004) Inverse association between circulating APRIL levels and serological and clinical disease activity in patients with systemic lupus erythematosus. Ann Rheum Dis 63:1096-103
Stohl, William; Metyas, Samy; Tan, Soon-Min et al. (2003) B lymphocyte stimulator overexpression in patients with systemic lupus erythematosus: longitudinal observations. Arthritis Rheum 48:3475-86
Tan, Soon-Min; Xu, Dong; Roschke, Viktor et al. (2003) Local production of B lymphocyte stimulator protein and APRIL in arthritic joints of patients with inflammatory arthritis. Arthritis Rheum 48:982-92
Kim, Kyoung Soo; Jacob, Noam; Stohl, William (2003) In vitro and in vivo T cell oligoclonality following chronic stimulation with staphylococcal superantigens. Clin Immunol 108:182-9
Stohl, William; Cheema, Gurtej S; Briggs, William S et al. (2002) B lymphocyte stimulator protein-associated increase in circulating autoantibody levels may require CD4+ T cells: lessons from HIV-infected patients. Clin Immunol 104:115-22
Stohl, William (2002) B lymphocyte stimulator protein levels in systemic lupus erythematosus and other diseases. Curr Rheumatol Rep 4:345-50
Roschke, Viktor; Sosnovtseva, Svetlana; Ward, Christopher D et al. (2002) BLyS and APRIL form biologically active heterotrimers that are expressed in patients with systemic immune-based rheumatic diseases. J Immunol 169:4314-21
Stohl, William (2002) Systemic lupus erythematosus: a blissless disease of too much BLyS (B lymphocyte stimulator) protein. Curr Opin Rheumatol 14:522-8
Cheema, G S; Roschke, V; Hilbert, D M et al. (2001) Elevated serum B lymphocyte stimulator levels in patients with systemic immune-based rheumatic diseases. Arthritis Rheum 44:1313-9

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